Process of making hydraulic cement.



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HERMAN BROWN, OF KINGSTON, NEW YORK, ASSIGNOR OF NE-HALIF TO WILLIAM:

R. l/VARREN, OF NEW YORK, N. Y.

PROCESS OF MAKING HYDRAULIC CEMENT.

No Drawing.

To aZZ wlz am it may concern.

Be it known that I, HERMAN E. BROWN, a citizen of the United States, and a resident of Kingston, county of Ulster, State of New York, have invented certain new and useful Improvements in Processes of Making Hydraulic Cement, of which the follow- I ing is a specification.

My invention relates to improvements in processes of making hydraulic cement and more especially to a process in which useful potash or other alkali metal salts may be obtained as a by-product.

The main object of the invention is to provide a process in which hydraulic cement may be obtained directly from feldspar (orthoclase) or equivalent materials, and in which substantially all of the raw product except moisture and CO, is converted into useful and valuable materials such as hydraulic cement and potash salts.

Tn carrying out my process in the preferred form I take the feldsparv and fuse it under oxidizing or non-reducing conditions in a suitable furnace with a suflicient quantity of calcium chlorid to furnish sufficient chlorin to combine with the potassium in the feldspar and witha suflicient quantity of calcium carbonate to bring the CaO content in the resulting material up to between per cent. and per cent. spect magnesia is to a certain extent the equivalent of lime, so that whenever I speak of the lime content being between 40% and 55%, or about 50%,1 mean lime 'or its equivalent. The calcium chlorid combines with the potassium in the silicate forming potassium chlorid, which is volatilized and may be collected by suitable well known condensing apparatus. The resulting slag'may be about the following compositioisilicaper cent, alumina lOpetcent; calcium oxid 52 per cent, rem'amderh percent. The fused material as allowed to run-from, the

furnace either directly or from a ladle, preferably onto a rotary drum, so that it is distributed in finely divided particles in achambcr filled with a spray of an aqueous solution of an alkali metal or alkaline earth sulfate such as magnesium sulfate. The magnesium sulfate being in aqueous, solution (say in a 5 per cent. solution) and coming into contact with the particles of the melted material, the water of the solution is quickly evaporated, thereby breaking up the Specification of Letters Patent.

In this re- Patented Jan. 52, mils.

Application filed November 16, 1914. Serial No. 872,368.

volatilizablecompound of potassium or other alkali's, and instead of using calcium carbonate any other'su1tabiecalcareous material may be used which will increase the- Gat) content of the resulting product to the proper percentage. Likewise, other suitable water soluble salts of the alkali forming metals may be injected into thehot material in the second step of the process and in some cases other materials such as iron salts, etc, the idea'being thatin the second stage of the process the necessary ingredients are added in order to increase the'hydraulic proper-ties of the material to-produce a hydraulic cement, which ingredients vary. according to the nature of the base material operated upon, and the particular kind or quality of hydraulic cement desired. I believe these material act to form in the finished cement a certain amount of Sorel cement or its equivalent, which gives the desired hydraulic properties. I use the term alkali forming metal to include both the alkali metals and alkaline earth metals. The second step of the process changes" the character of the melted materialand renders it suitable for production of a hydraulic cement, because is subsequently added a sufficient amount of plaster or gypsum in order to produce the desired time of set in the cement.

While speaking of the salt which is brought into contact with the hot slag as being in solution I use the term solution. in its most general sense, so asto include, for instance, liquid suspensions and molten baths.

Instead of using the calcium chlorid above mentioned, calcium carbonate alone may be used in the first step of the process. Thus if a double silicate ofpotassium and aluminum be taken having substantially the following composition: silica 65%, alumina 18%, potassium oXid 14%, and traces of ferric, sodium, calcium and magnesium oxid, and these materials combined with a comparatively pure limestone or marble in proportion of 100 parts of the double silicate to 170 parts of the calcium carbonate, a fused product is produced, of about the following composition: silica alumina 10%, calcium OX 1d 52%, remainder 3%. These materials melt very easily, and at a temperature of 200 to 300 .centigrade lower than is required for the manufacture of Portland cement, that is, a temperature of. about. 1300 C. This renders their furnacing a comparatively simple matter, the' struction of the furnace which cools the bined in the proportions as last stated, for I proved very disadvantageous. in high silica.

escaping gases. If the materials are comevery 100 pounds of orthoclase it is possible,

if full recovery of all the potash is made,

.secure 24.7 pounds of potassium, carbonate. Every barrel of cement wouldi'equire approximately 200 pounds of orthoclase if allowances are made-for impurities in the limestone and for additions of ash and magnesiu-m'sulfate and gypsum, which may be added in the second step; therefore, for every barrel of hydraulic cement produced from such materials, it would be possible, if full recovery is made, to ,obtain 49.5

pounds of potassium carbonate. By carrying-out the fusion under oxidizing or nonreduoing conditions, the production of sul fids and metallic pellets is preventedw-hich have hitherto. given much trouble and cement produced in the manner stated.

I It will be understood a that various cal careous materials may be used-in the fusion of the silicious material, although calcium carbonate, except as to the special salt used to unite with the potash, is'preferred. Calcium sulfate, for instance, may he used but it is not as satisfactory because S0, is liberated-only' at a comparatively higher temperature, audit is more difficult to make accment when usingthis mineral.

Bythe use of my improved process orthoclase or potassium or other alkali metal silicate rocks or other silicious material may be used for the production of a i hydraulic cement, and atthe. same time give:

as a by-producta relatively higher percent: age of volatilized potash or other alkali than has been possible to obtain from any previous process by furnace treatment of which I am aware.

Although I have described my -improvements in great detail and with respectlto certain particular embodiments thereof, nevertheless I do not desire to be limited-t0 such details except as clearly specified; in

the appended claims, since many changesand modifications may be made'without parting from the spirit and scope ofmy invention in its broader aspects.

improvements, whatl claim as new and desire to secure by Letters Patent is :e-

1. The process of obtaining cement and potash from feldspar, which consists in fusing feldspar with a suflicient quantity of calcium chlorid to furnish combinable chlorin for all thef'potassium and a sufficient quantity of calcium carbonate to bring, the Ca() content of the resulting fused ma: terial up to between 40% and 55%, collecting the volatile potash salt, and a ingthe material while-molten with an aqueous solution of magnesium. sulfate to produce hydraulic cement.

2. The'process ofobtaining-cementand';

potash from feldspar, which consists in fusing the' feldspar under noiureduei-ng conditions with a suflicient quantity of a,

halogen salt to combine with the potassium and a sufficient quantity of calcium saltfto bring the CaO content of the resulting rcementup to between-40% and 55%, collecting the volatile potash salt, and treating the molten product while molten withone or more salts. of alkali forming metals in-solution capable of increasing the hydraulic properties of the resulting product-to produce hydraulic cement.

3. The process of obtaining-cement andalkali' salt from alkali bearing silicates, which consists in fusingthe silicious mate rial with a sufiicientquantity of ahalogen salt tocomhinewiththe alkali anda sufficient quantity of a calcium salt to bring the CaO content :of the ;resulting product up to between 40% and 55%, separating out the alkali salt, and itreat-ingr the residual material while molten with a Sorel cement-form-.

ing salt in solution-to formvS-orel cementor its equivalent-in the finished cement and increase the hydraulic properties of the hydraulic cement in; which the CaO content is between.0% and 55%.

4 The process of obtaining cement and potash from-.potash bearing silicates, which consists in filming the silicious material underfnon reducing conditions with asu-' ficient quantity of a halogen salt which supplies the required amount of halogen to combine with the potassium and with a calcium compound, separating out the potash salt, and treating the melted product while molten with a suitable salt in solution capable of increasing the hydraulic propertiesthereof to produce hydraulic cement.

5. The process of obtaining cement and potash from potash and aluminum bearing silicious material, which consists in combining the siliciou s material with calcareous ina terial to combine with the potash and bringing the CaO content of the resultant fused material up to between 40% and removing the-potash salt, and treating the remaining product while molten with one 'ormore salts of alkali forming metals in solution capable of increasing the hydraulic properties thereof to produce hydraulic cement in which the Cal) content is between 40% and 55%. v I, 1 Y

6. The process of producing cement and alkali salts from aluminum and alkali hearing silicious material, which consists in fus ing the silicious material with calcareous material under nonreducing conditions, collecting the volatile alkali compound br com pounds, and then treating the resulting slag while molten with a suitablesalt in solution capable of increasing the hydraulic properties thereof to produce hydraulic cement.

7. The process of producing cement and potassium salts from aluminum and potass um bearing silicious material, which conslsts 1n fusing the siliclous material with calcareous materal under oxidizing condi-' tions, collecting the volatile potassium compound or compounds, and then treating the resulting melt with the necessary reagents in solution capable of increasing the hy- 'drauhc properties thereof to produce hydraulic cement.

8. The process of obtaining potash and cementfrom feldspar, which consists in fusing the feldspar with calcareous material, collecting the volatile potash compound, and then treating the resulting'product while increase the hydraulic properties of the'cement.

10. Theprocess of producing cement from feldspar, which consists in fusing the same with a sufficient quantity of calcareous material to bring the CaO content of the resulting product up to between 4t0% and 55% andthen treating this product while hot with liquid salts capable of increasing the hydraulic'properties thereof to produce hydraulic cement in which the CaO content is between 40% and 55%.

11. The process of obtaining cement and potash from potash bearing silicious mate rial which consists in fusing the material with a suflicient quantity of any suitable chemical reagent which produces an easily volatilizable potassiumcompound and a sufficient quantity of calcareous material to bring the CaO content of the resultant cement up to between 40% and 55%, collectthe volatilized potash compound, and treating the fused product while molten with an aqueous solution of one or more salts of alkali forming metals capable of increasing the hydraulic qualities thereof to produce hydraulic cement.

In testimony whereof, I have signedlmy name to this specification, in the presence of two subscribing witnesses.

HERMAN E. BROWN,

W'itnesses GORHAM Cnosnr, EDWIN Snonn.

testes of this patent may be obtained for five cents each, by addressing the Commissioner of Pate'rts.

- Washington, 33. 3. 4 1 

